Currently, serial communication is an extremely important and commonly used communication mode between embedded systems, such as a single-chip microcomputer and a digital signal processor (DSP), and between an embedded system and a personal computer (PC) or a wireless module.
FIG. 1 shows an architecture in which multiple serial ports in a chip in the prior art communicate with multiple serial port devices outside the chip by using a signal interface, where the signal interface is an interface for a serial port inside the chip to communicate with a serial port device that is outside the chip and corresponding to the serial port. The signal interface includes a Tx interface and an Rx interface, where the Tx is a signal transmitting interface, and the Rx is a signal receiving interface. Each serial port inside the chip sends data to a corresponding serial port device by using the Tx interface of the signal interface, and each serial port inside the chip receives, by using the Rx interface of the signal interface, data sent by the corresponding serial port device, so as to implement communication between each serial port and the corresponding serial port device, for example, communication between a serial port 1 and a serial port device 1, and communication between a serial port 2 and a serial port device 2.
In consideration of factors such as costs and power consumption, only one signal interface is designed during chip design. Therefore, in a case in which a quantity of signal interfaces of a chip cannot be increased, multiple serial ports inside the chip communicate with respectively corresponding serial port devices by using the only one signal interface, which causes a communication conflict.